I really like Miko's character. I don't like Shiori tho, idk, she doesnt really have any good character development, or story, and she looks evil all throughout, only thinking about Hinako as food. And I guess the romance doesnt click too, idk, maybe if its Hinako and Miko then I'll understand cause they have a fix backstory.
As for the cliffhanger tho, I think its a bait and when Miko said "evil monsters" she's talking about Shiori, who literally is an evil monster who want to eat Hinako. Maybe Miko was just looking for a chance to get close to Hinako and run off with her. So yeah, that's my take. If ever that Miko really ate her or her dying, well idk, the story just sucks if its only like that, the author just wasted a good character or actually the best character in the entire series.